NOBEL Prize and Oscar-winning former US vice president Al Gore has become the second largest shareholder in €1bn-valued Irish plc Kingspan.

Gore's private equity firm Generation Investment Management has doubled its stake in Gene Murtagh's Cavan-headquartered insulation firm and now holds a near 12 per cent chunk of the business. Gore's stake is worth close to €120m. The Kingspan stake is Generation's largest single investment in a listed firm.

Climate change activist Gore co-founded Generation Investment Management after his bid to become US president failed in 2000, when George W Bush was elected in the wake of the "hanging chads" controversy in Florida. Gore serves as chairman of the group, which invests in green, socially responsible and sustainable firms.

His co-founder David Blood was chief executive of Goldman Sachs Asset Management, which has led to the firm being nicknamed "Blood and Gore". Former Irish President Mary Robinson has advised the firm.

Market sources have indicated that Kingspan executives have met with Gore and his team at Generation Investment Management. The company declined to comment, saying that it did not discuss its shareholders.

Gore's buyout firm first started quietly purchasing Kingspan shares last year. Steady buying saw its stake pass 10 per cent in May, with recent share deals bringing its holding up to nearly 12 per cent. Kingspan's share price has more than trebled since February, netting major paper profits for Gore's outfit.

"We invest in long-only, global, public equities with a concentrated portfolio of 30-50 companies. We invest in high quality businesses and management teams whose securities are attractively priced to deliver excess returns over the long term," according to the company. Last year the company raised €480m for a climate change fund. It has also closed a near €1.4bn global equity fund. While Kingspan is the largest single investment by the group, it also holds positions in firms like eBay, Becton Dickinson, Amdocs and Deere. "Generation has a policy of not commenting on any of its investments," according to a spokesman for the London-based private equity firm.

Gore has become increasingly active in business in recent years. Apart from chairing Generation Investment Management, the Tennessee born activist sits on the board of Apple. He is also an adviser to Google and is a partner in IT venture capital firm Kleiner Perkins Caufield & Byers. Gore's global warming movie An Inconvenient Truth won an Oscar in 2007, while he shared the Nobel Peace Prize with the Intergovernmental Panel on Climate Change the same year.

The sheer scale of the Gore investment in Kingspan will provide a massive fillip for the Cavan firm. Kingspan was founded in the back of a pub in Kingscourt, Co Cavan, by brothers Eugene and Brendan Murtagh almost 40 years ago. The company is now run by Gene Murtagh Jr.

Although widely described as a building materials company, Kingspan is one of the most innovative "green" businesses on the island. Teams of company scientists and chemists are working on ways of reducing heat emissions by improving high performance insulation. It is estimated that around 40 per cent of carbon emissions come through poorly insulated buildings.

The company also invented the world's first carbon neutral house -- the Lighthouse in Watford, England. Kingspan has also diversified into solar energy through the purchase of Thermomax in 2007. It is also moving into the rainwater harvesting sector.